AndroidStudio——利用APIStore获取网络新闻

HttpJsonActivity

public class HttpJsonActivity extends AppCompatActivity {
   
    private Spinner channel;
    private TextView tv;
    private SimpleAdapter sa;
    private List<Map<String, String>> channelList;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_http_json);
        tv = (TextView) findViewById(R.id.tv);
        channel = (Spinner) findViewById(R.id.channel);
        channelList = new ArrayList<>();
        sa = new SimpleAdapter(this, channelList, android.R.layout.simple_spinner_item
                , new String[]{
  "name"}, new int[]{android.R.id.text1});
        channel.setAdapter(sa);
        new GetChannel().execute();

        channel.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                Map<String, String> map = channelList.get(position);
                String channelName = map.get("name");
                String channelId = map.get(channelName);
                String url = UrlUtil.newsUrl + "?channelId=" + channelId
                        + "&channelName=" + channelName
                        + "needContent=1"
                        + "&needHtml=1";
                new GetNews().execute(url);
            }

            @Override
            public void onNothingSelected(AdapterView<?> parent) {

            }
        });
    }

    //获取频道
    public class GetChannel extends AsyncTask<String, Void, String> {
   
        @Override
        protected String doInBackground(String... params) {
            return HttpUtil.HttpGet(UrlUtil.channelUrl);
        }

        @Override
        protected void onPostExecute(String s) {
            super.onPostExecute(s);
            if (s.equals("")) {
                Toast.makeText(getBaseContext(), "网络连接异常", Toast.LENGTH_SHORT).show();
            }
            try {
                JSONObject obj = new JSON